The invention relates in general to electrical cord sets. In particular, the invention relates to an electrical cord set constructed in part from an intermediate electrical component or a pre-mold pod for a molded plug which prevents stray strands from stranded conductors from being exposed from a finished plug.
One of the significant expenses associated with the manufacture of electrical cord sets is the cost of molding the electric plug. In part, this is because in typical prior art molded plugs the interior of the plug, with the exception of the metallic terminals comprising the contact blades and ground prongs and the single conductors connected thereto, was completely filled with plastic or rubber which made the plugs relatively expensive. In addition, because of the relatively large volume of material molded in the plug it was difficult to obtain a smooth and aesthetically pleasing surface on the outer portion of the plug. In order to reduce the cost associated with the manufacture of cord sets, others have developed pre-molds or pre-mold pods consisting of multiple plastic components having a ground prong and power blades as well as singles connected thereto. Unfortunately, one of the problems associated with plug manufacture in the past which does not appear to have been significantly alleviated by the use of pre-molds is the problem of strays. Strays are strands of multiple strand conductors which are separated from strands connected to the crimped termination of a ground prong or a connector blade. In part, in order to avoid the problem of strays, pre-molds have been used in an attempt to trap all of the strays entirely within the pre-mold. However, many of the prior art pre-molds suffer from the problem that the strays are still long enough to exit a portion of the pre-mold due to relatively short spans between the crimped termination areas and the openings in the pre-mold from which the strays might exit.
The prior art also teaches the use of molded preforms which are assembled with electrical connectors and wires before a further molding step. For instance, U.S. Pat. No. 3,668,779 to Turner discloses, in FIG. 4, a pre-mold insert 21 having various recesses for receiving a pair of terminals 11 joined to stranded conductors 12. The mold itself receives the terminals 11 with the insert being positioned over the conductors with barrier walls 25 and 25a of the insert spacing the stranded conductors 12 to prevent shorting by a loose strand. The outer covering or post-mold is then molded about the insert. This insert is only a base and the mold itself performs the function of the lid to complete the encirclement of the stranded conductors.
U.S. Pat. No. 4,405,194 to van Lierop discloses a pre-mold insert arrangement including a base 3 holding space connector pin 7. A cap 1 covers the rear of the base 3 after attachment of the stranded conductors to the pin 7. The base has a recess 19 for receiving a fuse holder 5. The cap 1 prevents liquid plastic from flowing into the fuse recess 19 during injection molding of the plug body 25, as may best be seen in FIG. 2.
U.S. Pat. No. 4,043,603 to Suverison, et al. discloses a molded plug connection including a preformed insert 22, as may best be seen in FIGS. 2 through 6. The insert is described at column 2, lines 18 through 29. It includes a front plate 40 with a turret 42 extending rearwardly therefrom and having spaced wire-receiving channels 46. The channels 46 are open for most of the length of the insert 22.
U.S. Pat. No. 4,398,785 to Hedrick discloses an inner body 42 which is injection-molded about the contacts 12 and the connectors 14 which are attached to the contacts 12. Thereafter, an outer cover 50 is injection-molded about the inner body 42.
Although these pre-molds provide convenient intermediate electrical components for assembly of electrical plugs they do not prevent stray strands from extending from the finished plug. What is needed is an intermediate electrical component for a plug of a cord set which prevents stray conductor strands from exiting the plug surface where they might cause a shock hazard.